1. Field of the Invention
The present invention relates to an information processing apparatus, an information processing method, and a program.
2. Description of the Related Art
With development of recent information techniques, various information processing apparatuses capable of displaying predetermined information of PDA (Personal Data Assistant), portable telephone, music reproduction device, personal computer, display device, and the like are being developed, and needs of the user putting importance on portability thereof is rapidly increasing. The information processing apparatus is becoming miniaturized in order to respond to the needs of the user.
According to the miniaturized information processing apparatus, a display screen such as a monitor for displaying the predetermined information is also miniaturized. In such compact screen, the information that can be displayed all at once and the visibility of displayed information are limited by themselves when browsing various contents such as contents, maps, pictures, text data, table calculation data, sentence data, and illustration data on the Web. Thus, in such information processing apparatuses, operation for changing the scale and the scroll of the content (display target) is frequently carried out.
An input device which is operated by detecting the contacting position of the finger or the like of the user and which outputs a predetermined signal such as a touch panel and an input device described in Japanese Patent Application Laid-Open No. 2003-337649 is developed, and a technique of changing the scale and the scroll with such input device is developed. Among them, the changing (scrolling) of the displayed position (range) in the content is a scrolling operation generally carried out in a GUI (Graphical User Interface), and methods such as a method by a scroll bar, and a method of dragging one point on the screen while pressing the point with a mouse, a finger, a touch pen, or the like are often used. A method of specifying the magnification with a menu, a method by a magnification scroll bar, and the like are often used to change (scaling) the display magnification of the displayed content.
However, such scaling operations have low intuitive performance for the user compared to the scrolling operation carried out by directly dragging the screen, and thus becomes a cause the operability of the information processing apparatus is unable to be enhanced.
As described in Nobuyuki Matsushita and Jun Rekimoto, “HoloWall: Designing a Finger, Hand, Body, and Object Sensitive Wall”, Proceedings of UIST'97, 1997; and Jun Rekimoto, SmartSkin: An Infrastructure for Freehand Manipulations on Interactive Surfaces CHI2002, 2002, an information processing apparatus capable of, through the use of an input device (multi-touch interface) capable of recognizing (multi-touch) the operation point (e.g., touch position in the touch panel) to be operated by the user not at one point but at two or more points, controlling scaling according to the distance between two points is developed. Such information processing apparatus can adjust scaling by opening and closing of two fingers or the like touching the input device.